The error code 422 appears when something has been entered into one of the boxes that is not valid. For example, entering an e-mail address that isn't in a valid format, or entering an authentication code that has expired, or isn't a valid 5 letter code.
Some common examples that might cause this are putting a space or other invalid character in the e-mail address, using a comma instead of a full stop by mistake, or forgetting to put the .com on the end, or using .com when the address has another extension, such as .co.uk.
This may also mean that you are entering your email when you should be entering a 5 digit authentication code, or the authentication code you are entering is not valid or has expired. Make sure the authentication code you are entering is exactly 5 digits long (i.e. ZAOYC). If the code is older than 15 minutes, then try restarting the game and start again, entering your email first, and then the authentication code.